Ntjts limited



Jan. 27, 1931. GARRARD 15790538 LOCK my:

Filed June 30, 1928 X 1 IN VEN TOR Charles (far/11ml I BY 2 Patented Jan. 27, 1 93 1 CHARLES GEORGE GARRARD, 0F

LONDON, ENGDAND, 'ASSIGNOR "r0 EVERTITE LOCK- NU'rs LIMITED, or LONDON, EN AN JA BRIrIsHcoMPANY LOCK NUT Application filed June 30, 1928, Serial N'o. 289,507, .and inlGreat Britain Iu1y'1 -2, 1927.

This invention relates to locknutso-f the kind wherein the locking action depends upon resilient deformation of the nut body produced by relative displacement of parts J work-piece by radial or like slitting of the nut from one end towards the internal an nular grooving to provide for more liberal deformation involves a further manufacturing operation and is likewise unsatisfactory.

The object of the present invention is to overcome such disadvantages as the above and in general to provide locknuts both eflicient in action and cheap and simple to manufacture.

According to the present invention, the nut is rendered resiliently deformable to eii'ect the locking in the manner above indicated by providing internal substantially helical grooving distinct from the nut thread.

The helical grooving may be of any suitable section and depth and of constant or variable pitch preferably being of opposite hand to the thread and such as to give adequate resilience. The said grooving may extend Wholly or partly through the nut and is adapted to leave one or more internal portions capable of relative displacement for causing elastic deformation of the nut under the pressure produced by contact of the end of the latter With the workpiece or abutment. The nut may be bevelled on one or both ends, such bevel extending preferably from a relatively flat portion around the bore conveizly to the outer Walls of the nut so as to more or less localize the contact pressure on the end regions of i the lsometvhat Wedge shaped deformable portions leftv adjacent the groov- 1110. p

To nninimize .tl1e 1likelil109d of rust, the helical groove maybe filled in, wholly'or in p'artfwith any suitable soft, pl astic material.

In the preferred construction the helical grooye extends from endfto endof tliebore and v1s ,of ,V shape .in cross, section, and 'i's of considerably {greater depth-than the thread v In order that the; intention I may be b o er understood, it willnow be described with reference to the accompanying drawing, the single figure of whic'hushews a 'sec tion':'rl elevation of a preferredform ofjnfut constructed according to the invention and 'in which a 'is thebo'dy of the nut which is formed "with abore having an ordinary thread '6. Intad- ,dition theinut is al'so'form'ed with a helical groove c whiche'xtends from end to'en'd of hand to the thread in x the nut moreover the grooves is ofconsiderably greater depththan the depth of the;thr'ead.

" The ends ofthe nut are bevelledat d in a convex mannerand this convex bevellin'g extends .from the Walls ofthe n'utto alflat portion 6 around the bore. In some cases only one endof'th-e nut need'be bevelledand although it is preferred to'us'e a fiat portion such as a in connection with tho bevclled end or ends, 111 some cases the flat portion or portions may be dispensed with. V

Th'e'helical groove may be ofany other ample theinvention maybe successfully ap plied to nuts 'having'a bore of one half an inch diameterdow'nwards.

Successful Veresu'lts have been obtained in i o o Y 965 the bore and is of V shape in cross section.

'The helical groove c is of desiredpitch and as shown] on thedrawing is ofthe opposite practice with a standard B. S. F. nut of mild steel of a tensile strength of about 30 tons per square inch with the invention applied thereto, a single heli al groove being employed ot the opposite hand to the thread, having a pitch of of V shape in cross section, the angle at the apex of the V being 35 degrees and the depth of the V being twice the depth of the thread, the nut having one end only bevelled, the angle of the bevel being 15 degrees to the horizontal.

\Vith nuts constructed according to the invention, owing to the provision of the helical groove, a certain clamping action is produced between the threads of the nuts and the threads of the bolt, due to the bevelled end screwing down upon the work piece and causing the elastic deformation between the groove and separated threaded parts, attributed to the transmission of the pressure through the material of the'nut.

Having now particularl described and ascertained the nature of my said invention and in what manner the same is to be performed. I declare that what I claim is:-

l. A locl: nut of the kind wherein the lociing is obtained by resilient or elastic deformation when the nut is screwed up against the work-piece or abutment, in which internal parts of the nut body adapted to become relatively displaced to provide such detormation are formed by providing internal substantially helical grooving distinct from the nut thread.

2. A lock nut according to claim 1 having the grooving deeper than the screw thread.

3. A lock nut according toclaim 1 in which the nut body is provided with helical grooving having relatively displaceable screwed parts thercwithin, the helical grooving being of opposite hand to the nut thread.

i. A lock nut according to claim 1 in which the nut body is provided with helical grooving having relatively displaceable screwed parts therewithin, the helical grooving being of opposite hand to the nut thread, said grooving extending throughout the length of the nut.

A lock nut according to claim '1. wherein at least one end face of the nut is bevelled, such bevel extending from a relatively [lat portion around the bore convexly to the outer walls of the nut.

(l. A look nut according to claim l in which the helical grooving is of V shape in cross section and oi? considerably greater depth than the nut thread.

7. A lock nut comprising an internally threaded body, having an internal substantially helical grooving distinct from the nut thread providing elastic deformable portions throughout the length of said body, and said body having a convex bevelled work-engaging end face whereby said grooving will be deformed upon forcible engagement with a worlopicce.

8. As a new article of inanufin'ture a lock nut, having a threaded bore, convex ends, and a. helical V-shaped groove in the bore and extending the length thereof, the groove being of opposite hand to the threads oi? the nut and ot' a depth about twice the depth of said threads.

In witness whereof I aflix my signature.

CHARLES GEORGE GARRARD. 

